1. Field of the Invention
The present invention concerns a safety sealing device capable of being used for numerous applications, the integrity of this sealing device being checkable by preferably automatic, fixed or portable electronic means.
2. Description of the Related Art
On numerous occasions it is necessary to be able to ensure that the contents of some recipient have not been fraudulently modified during a storage period or during transportation, for example, or since the moment when the sealing was affixed to the recipient, respectively.
The term recipient used here is of very general range, it may be a building of which the door and the windows have been sealed, just as well as a measuring apparatus of which the adjustment rust be preserved or a box whose contents must not be altered, etc. Likewise by sealing, it is not absolutely necessary that the recipient in question cannot be opened, it may also be an operation of marking an object, for example a suitcase at the time of a trip, said marking having to remain attached to the object without a possibility of being taken off it, exchanged or altered before the end of said trip, or before the accomplishment of a checking operation, respectively.
To ensure this, there is generally a seal on the recipient or the object in question, this seal generally being made up of a piece or a strip of paper, cardboard, cloth, plastic, or thin metal, a portion of which is fixed to a first part of the recipient, while another portion is fixed to a second part of the recipient, the opening of the recipient, or the separation of the two parts or the opening of the seal, respectively, being able to take place only by tearing the sealing strip; the sealing piece or strip generally has a shape and size adapted to the type of recipient to be sealed. A sealing device of this type, provided for the sealing of a bottle, is described for example in FR-A-2,658,166.
Another prior art device is made up of a wire forming a loop in order to prevent the opening of a recipient, or to be able to be taken off the object to which it is fixed, respectively, two strands of wire closing the loop being joined by a wax or lead seal.
Such sealing devices according to the prior art include the main drawback of being able to be relatively easily broken. It is generally possible to defraud them by taking the necessary time and/or precautions to carefully detach or unstick one of the portions of the device and to replace it after having emptied or exchanged the contents of the recipient. In the case of a simple marking, it is possible, in the same way, to modify or exchange said marking. Moreover, a check of the integrity of the sealing can take place only piece by piece, by a visual examination of each sealing, which is long and expensive.
A sealing device capable of being checked electronically is described in U.S. Pat. No. 4,751,500. This device is specially adapted in order to check the circulation of merchandise in sales premises in order to avoid the theft thereof. It is designed to be used in premises of which the entrances are equipped with electronic checking means. A sealing device is disposed on each unit of product to be sold, the unsealing of the product being able to be done only by means of a special tool which does not destroy the sealing device. The device described here can be used only on specific premises.
Another electronic-check sealing device is described in EP-A-0 177 394. In this case, the seal is composed of an ultrasound cavity connected to a receiver transducer and to another transmitter transducer. These transducers are electrically connected to a probe ensuring the connections to the checking circuits. The unsealing of the seal causes a deformation or destruction of the ultrasound cavity, thus modifying its response to a given excitation. The drawback of this device is that it is necessary to electrically connect each seal to the checking device in order to energize the seal and check the response thereof.
EP-A-0 377 257 describes a device for the identification of objects, each of them bearing a seal provided with a code. The code can be remotely read electromagnetically, but for this the seal needs to be fed by its own voltage source. It is not anticipated that the code may be modified by destruction of the seal.